New saliva test set to help farmers breed worm-resistant sheep
Parasitic worms can jeopardise the sustainability of farming operations. Image: jodie777 - stock.adobe.com
A test developed from a Federation University research project allowing farmers to perform a simple saliva swab on sheep to detect their resistance to worm infection is poised to become a commercial reality and make the jump from the lab to the farm.
The test, developed by Veterinary Bioscience senior lecturer Dr Sarah Preston, aims to help farmers breed worm-resistant animals while cutting farm costs by limiting the reliance on chemicals.
Parasitic worms in sheep and goats pose a significant global challenge to meat and wool industries. Infestations can negatively impact livestock's health and reproduction rates and reduce wool or meat production, jeopardising the sustainability of farming operations.
The primary control method used to combat these infestations is the application of anthelmintics, also known as drenches. But historical over-reliance on these chemical treatments has led to an increase in worm resistance, rendering these solutions less effective over time.
"There is widespread drug resistance on a lot of farms, so one sustainable option is to start breeding the genetics into the sheep for a stronger immune response to worms," Dr Preston said. "Sheep that are naturally more resistant to worms require less chemicals".
"Some sheep studs are breeding for worm resistance already, but these are with faecal tests called worm egg count tests, which can be effective but take a long time. Farmers need to collect individual faeces from sheep. In dry conditions, you cannot get the infection required for the accuracy of the test. That is a big problem for many farmers at the moment."
Dr Preston is hopeful the saliva test she has developed is a universal solution to a global problem. Other saliva tests developed overseas have had success in their home markets, but the results successes didn't translate when tested in Australia. The tests are carried out by measuring an animal's immune response to the infection from the worms rather than looking for evidence of a worm infection in the sheep's faeces.
"We've just carried out tests at one stud where we've been able to show that by collecting the saliva, which is much quicker than collecting faeces for the farmer, and testing that in our lab, we can measure an antibody response to the worm," Dr Preston said.
"By measuring that antibody response in the sheep, we will be able to get what is called a breeding value – which is a genetic component of the test – and then farmers will be able to select which sheep are genetically more resistant to worms and start breeding that into their flock. It is a natural selection process where the breeding rams are selected to change the flock's genetics.
"Sheep studs have been breeding particular traits into their flock for years by selectively looking at how good their wool is or how good their feet are, or those sorts of things. Now, much more science is available to back that up."
The project has received backing from BeanStalk AgTech – an innovation advisory and venture-building company that supports industry leaders, start-up innovators, investors, and government bodies to advance sustainable, ethical, and responsible food systems.
Dr Preston's proposal made the top 24, and she was invited to participate in a 12-week program to develop the proposal. This involved pitching the concept at the global agrifood technology and innovation event EvokeAg in Brisbane earlier this year about how the project would help the industry and how the product could be commercialised and backed with a business model.
From that, she was offered a spot in the BeanStalk AgTech venture building in-residence 11-month program and has created the Federation University-backed company SwabTec to develop and market the test.
Funding from Dr Preston's participation in the BeanStalk AgTech program has allowed the business to cover some equipment, put structures in place and cover start-up legal costs. The business will operate from a high-tech laboratory at Federation's Mt Helen Campus.
"We're looking to recruit farms now to participate. We need to validate the products on multiple farms now – we are working with Sheep Genetics, the genetic evaluation service of the Australian sheep industry, who want to see the results from 9,000 tests, and then they'll do their own analysis on it to make sure that it fits within their breeding program," Dr Preston said.
"We have 30 studs participating and we're waiting to test their sheep because it's been so dry – the worms haven't been around as much. We have to collect the samples at the same time as the faecal tests, which will be done for a big benchmarking exercise.
"One of the advantages of our saliva test is you don't need to have such a high worm infection because that response comes a lot earlier than the eggs do. We just need to wait for the conditions to be right for the other tests that we're trying to compete against."
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